This invention is directed generally to the field of cleaning apparatus or systems for contact lenses and more particularly to a novel and improved vibrator actuated lens cleaning system.
With the advent of soft contact lenses and extended wear contact lenses, both of which are porous as compared to the older "hard" lenses, development of improved methods and apparatus for assuring cleaning of lenses has assumed new importance. Because of the porous nature of these types of contact lenses, as well as the relatively longer periods of wear for which certain lenses are designed, thorough cleaning is necessary to remove residue from proteinaceous and fatty body fluids and the like which have accumulated during wearing. In this regard, it will be appreciated that the relative porosity of these types of contact lenses tends to encourage collection and retention of such body contaminants. This results in a buildup of residues not only on the surfaces of the lenses but also within the pores thereof.
Such soft and extended wear lenses are generally hydrophilic, and porous as indicated above, such that the proteinacious and fatty materials tend to invade the porous matrix of the lens. For cleaning, such lenses are often subjected to an enzymatic cleaner solution of various known types and generally available. The enzymes in these cleaning solutions tend to destroy or consume the proteinacious and fatty substances which build up on the lenses after extended periods of wearing. After the lenses have been subjected to the enzyme cleaning solution, however, they must be thoroughly cleansed before placement on the eye. That is, since these enzyme solutions are hostile to bodily tissues, they would have an adverse effect if permitted to remain within the porous lens after it is replaced on the eye. In this regard, it should be recognized that the enzyme cleaning procedure generally involves leaving the lenses in the enzyme solution for a period of 6 to 12 hours so that there is often considerable penetration of the porous lenses by the enzyme solution. Accordingly, it is important that the lenses be thoroughly rinsed and any residual cleaning solution removed following the cleaning or disinfecting procedure, to assure that those materials which attack protein or protein-like substances will not remain on the lens when it is replaced in the wearer's eye.
The prior art relating to rinsing after enzyme cleaning has proposed utilizing a rotary unit that would spin the lens in a rinsing solution-filled storage case, for example as shown in U.S. Pat. No. 3,623,492. However, the constant rotation of this type of device tends to cause more agitation or swirling of the rinsing solution or water at the periphery of the case rather than at the central portion where the lens or lenses are disposed. Hence, there may be insufficient agitation of the rinsing solution or water over the entire surface of the lenses, as is necessary to effect thorough rinsing.
In general, any lens-washing container must not only contain the lens but also have sufficient open area to permit agitation of the rinsing solution or water therein. However, the solid lenses in the liquid solution tend to migrate to the area of least agitation or net liquid flow within the case. Hence, relatively thin lenses have a tendency to in effect "roll up" and migrate toward or even pass through the openings provided for liquid flow, and reach areas of minimum or no flow. This defeats the purpose of agitation, resulting in possibly insufficient rinsing and penetration of the porous lens bodies to effect complete removal of the enzyme solutions and their residues.
Additionally, with a rotary device as anticipated by the above noted prior art require some form of seal where the rotary shaft or other rotation imparting member passes through or into the container. Providing a reliable seal between relatively rotating parts always presents problems in design and fabrication. Moreover, rotating parts tend to experience wear while in service, necessitating repair or replacement or possibly leading to unsatisfactory operation or even failure. Also, it is noted that the device shown in the above-referenced U.S. Pat. No. 3,623,492 is a manually operated device. Hence, there is some problem of possible user fatigue or simply failure of the user to operate the device for a sufficient length of time or with sufficiently vigorous action to obtain the desired rinsing or cleaning action.